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U ITED STATES PATENT OFFICE.

ROBERT HARDIE, OF HOBOKEN, NEW JERSEY, ASSIGNOR TO THE PNEUMATIC TRAMWAY ENGINE COMPANY, OF NEW YORK, N. Y,

COMPRESSED-Al R LOCOMO TlVE,

SPECIFICATI01\T forming part of Letters Patent No. 248,037, dated October 11, 1881, Application filed January 26,1881. (No model.)

To all whom tt may concern:

Be it known that I, ROBERT HARDIE, a resident of the city of Hoboken, in the county of Hudson, in the State of NewJersey, have in- 5 vented certain new and useful Improvements in Compressed-Air Locomotives, of which the following is a specification.

My invention relates particularly to locomotives in which compressed air is used as a motive agent, though it may be applied to steam or other locomotives.

In Letters Patent No. 216,611, granted to Robert Hardieand John James, June 17, 1879, is shown and described a locomotive-cylinder I5 provided at each end with suction and discharge valves, which provide, when the main slide-valve is held stationary at the center of its stroke, for drawing air into said cylinder and discharging it therefrom, thus utilizing the momentum of the locomotive in going down a grade or in stopping for pumping air, and thereby aiding in stopping or checking the speed of said locomotive.

The function of the locomotive-engine as a pump may be advantageous in "arious ways. If compressed air is used as a motive agent, the cylinders, when acting as pumps, may force air into the reservoir or reservoirs of the locomotive, and thereby store up power, and

c the air so compressed and supplied to the reservoirs may, with great advantage, be exhausted by said cylinder from a vacuum reservoir or chamber for operating vacuum-brak es. When the locomotive-cylinder is used, as above 3 5 described, for a pump, if the pressure exerted upon the face of the main valve through the ports at the end of the pfstons stroke exceeds the pressure exerted upon its back it will be lifted and caused to chatter, and air will then 40 be discharged into the valve-chest; and the object of my invention is to provide means for holding the main valve to its seat when the cylinder is used as a pump, but which means will be acted upon by the motive agent when 5 the latter is admitted to the valve-chest by the opening of the throttle-valve and the main slide-valve relieved of all pressure except the pressure exerted by the motive agent upon its back.

In Letters Patent N 0. 203,729, granted May 14, 1878, to Robert Hardie, John James, and- James G. Cooper, there is shown a hollow slidevalve which serves as a chest or rcservoir'for the motive agent, and is provided in its lower side with ports for the passage of the motive agent to the cylinder. These ports reduce the area of the lower side of the valve upon which the motive agent within-it acts, and to prevent the valve from being lifted from its seat a swinging arm is pivoted above the valve so as to move therewith, and has its lower end con.- nected with a flexible diaphragm in the back of the valve. The said diaphragm is always pressed outward by the pressure of the motive agent within the valve, and is employed simply as a convenient means of connecting the valve with the swinging arm, which holds it to its seat.

To this end my invention consists in the combination, with an engine-cylinder, its slidevalve, and separate suction and discharge valves for air at each end of said cylinder, of a spring-actuateddiaphragm fixed in the outer side of the valve-chest and exerting, through suitable connections, a pressure upon the valve 7 5 to hold it to its seat when said diaphragm is not acted upon by a motive agent in the valvechest and when the engine is used as a pump, but which, when a motive agent is admitted to the valve-chest, is impelled upward, reliev- 8o ing the valve of all pressure except that exerted upon its back by the motive agent. The spring-actuated diaphragm preferably consists of an elastic steel disk held atits edge and having the bridge-piece, yoke, or other connection connected with its center, and I combine with the diaphragm means for adjusting or varying its pressure so as to cause it to exert more or less power on the bridge-piece or yoke, and through it'upon the valve.

The invention also consists in the combination, with the vacuum-chamber, of a vacuumbrake apparatus of a locomotive-cylinder provided at each end with separate air-suction and discharge valves, for exhausting air from 9 5 said vacuum-chamber when it is desired to stop or brake up a train.

In the accompanying drawings,Figure 1 represents a side view and partial section of an engine-cylinder and appurtenances embody- 10g ing my invention; and Fig. 2 represents a transverse section of the valve-chest, valves,

and appurtenances upon the dotted lines x .r, Fig. 1.

Similar letters of reference designate corresponding parts in both figures.

A designates alocomotive engine-cylinder. A designates the valve-chest thereof, and B B designate the two cylinder-heads.

O designates a main slide-valve, whereby the motive agent is admitted to and exhausted from the cylinder, and which is actuated through its val e stem or rod, 0, in the usual way.

D designates cut-oli' valves, adapted to slide upon the back of the main valve 0, and actuated by a rod or stem, D, which has right and left screw-threads, which engage with the cut-off valves, and, by turning said cut-olf rod or stem, serve to adjust. said valves nearer to or fartherfrom each other for varying the point of cut-ofiin the usual way.

So far as described all the parts are of ordinary construction and operate in the usual way.

When it is desired to stop a locomotive, the throttle is closed, and the reversing-lever is operated to bring thelinks to a dead-point and the valve to the center of its stroke, so that it will cut-off all communication between the valve-chest A and the cylinder A.

To enable the engine-cylinder to serve as a pumpcylinder, l fit in each of the heads B B one'or more suction-valves, E, and one or more discharge valves, F, as clearly shown in Fig. 1. In this instance only one suction and one discharge valve is represented for each cylinder-head, but more might be employed if necessary. The suction-valves E are arranged in cavities a in the heads, which communicate by means of passages b with the main exhaustport of the engine. The discharge-valves F are arranged in cavities c in the heads, which communicate by means of passages cl with a common discharge-passage, 0, extending lengthwise of the cylinder, and provided with an outlet-pipe,f.

It is obvious that after the valve 0 is adjusted to its central position the continued movement of the piston will draw air from the cavities a through the suction-valves E into the cylinder, and will discharge said air out through the discharge-valves F, and thence through the outlet to the locality where itis desired to use it. For instance, the air might be drawn down the exhaust-pipe and discharged into the reservoirs for compressed air, if such be the motive agent used or, the air so compressed might be employed for a presstire-brake; or, if desirable, the exhaust-pipe might be closed by turning a cock, and the air drawn into the cylinder be exhausted from the vacuum-chamber of a vacuum-brakeapparatus.

To provide for exhausting air from the vacuum-chamber of vacuum-brakes I connect to the exhaust-chamber in one head of the cylinder in which is the suction-valve E a hose, S, which may be connected to other hose carried by a car and communicating with a vacuum-chamber. The supplyof air to both ends of the cylinder is then drawn through the hose S.

In locomotives the two cylinders are con nected by means of a saddle, and this saddle may be made hollow and the hose or pipes for exhausting from vacuum-brakes be connected therewith. Both cylinders would then derive their supply of air from the vacuum-chamber of the brake apparatus. as the throttle is now shut off there is no considerable amountof pressurein the valve-chest A, and if sufficient pressure be produced at the end of the pistons stroke, it will raise the valve 0 off its seat and cause it to chatter, and will discharge the air into the valve-chest A instead of through the discharge-valves F.

I will now describe the mechanism employed for holding the valve C tightly toits seatwhen the cylinder is used as a pump-cylinder.

G designates a bridge-piece or yoke, which is arranged in the upper part of the valvechest A and bears at 9 upon the top of the projections or upward extensions 0 on the main valve 0.

H designates the cover of the valve-chest A, which has upon its upper surface an annular rib or facing-piece, h, upon which is bolted and secured by a second ring, i, asteel disk or diaphragm, I, forming between the top of valvechest cover H and said diaphragm I a chamber,j.

The diaphragm I may beregarded as fixed in the outer side or wall, in this instance the top or cover of the valve-chest.

The bridge-piece oryoke G has upon its top a projection or boss, which fits loosely in an opening or hole, k, in the chest-cover H, so that the compressed air or other motive agent admitted to the valve-chest may have free access through said hole or opening to the chamberj to act upon the diaphragm I.

In the center of the diaphragm I is a stuffing-box, J, which is secured to the diaphragm by a screw threaded nut or flange, l, and through this stuffing-box passes an adjustingscrew, K, which is screwed into the boss or projection upon the bridge-piece or yoke G, and is provided with a collar, m, which fits between said boss or projection and the stuffingbox J. If the screw K be unscrewed from the bridge-piece Gr one or two turns, its collar m, acting upon the end of the stuffing-boXJ, will deflect-the diaphragm I upward, and cause it, through its elasticity, to exert a downward pressure upon the bridge-piece oryoke G, and through it upon the back of the valve 0, when the throttle-valve is closed to shut off the motive agent from the valve-chest A.

The screw K may be unscrewed from the bridge-piece or yoke G, and the diaphragm I be thereby distended until the pressure of the said diaphragm is sufficient to hold the valve 0 to its seat against the upward pressure of the air compressed within the cylinder A, when It will be seen that the latter is used as a pump and the main valve Cis stationary. When, however, the cylinder is to be used as an engine-cylinder and the valve 0 reciprocated, it is desirable that it should be relieved of the pressure of the the latter against its seat, as before described.

L designates oil-tubes, which may be provided with oil-cups, and which supply oil through perforations it onto the bearing-surfaces 9 of the valve 0 and the bridge-piece or yoke G, and lubricate them.

Although in this example of my invention the spring-power which actuates the diaphragm in a downward direction is produced by'the elasticity of the steel plate of which thediaphragm is composed, I do not confine myself to such a diaphragm constituting of itself a spring, as it is obvious that I might form in the cover H of the valve-chest a cylindricchamher, and fit therein a piston-diaphragm, which would be impelled downward upon the bridgepiece or yoke G by the pressure of a separate spring, and would be raised by the action of the compressed air or other motive agent.

In lieu of the bridge-piece or yoke G the diaphragm H might be otherwise-connected with the valve.

I am aware that a diaphragm of spring metal has been used heretofore for balancing a slidevalve, and therefore do not claim this as my invention. My diaphragm has no tendency whatever to lift the slide-valve, but is employed to exert a downward pressure thereon.

What I claim as myinvention, and desire to secure by Letters Patent, is-

1. The combination, with an engine-cylinder, its slide-valve, and separate suction and discharge valves for air at each end of said cyllinder, of a spring-actuated diaphragm fixed in the outer side or wall of the valve-chest, and a connection through which said diaphragm exerts a pressure upon said valve to hold it to its seat when said diaphragm is not-acted upon by a motive agent within said valve-chest, substantially as and for the purpose herein specified.

2. The combination, with an engine-cylinder, its slide-valve, and separate suction and discharge valves tor air at each end of said cylinder, of a spring-actuated diaphragm fixed in the outer side or wall of the valve-chest and adapted to exert a pressure upon the valve to hold it to its seat when said diaphragm is not acted upon by a motive agent within said valve-chest, and means for varying the pressure exerted by said diaphragm upon said valve, substantially as specified.

3. The combination of the cylinder A, the slide-valve G, suction and discharge valves E and F at each end of said cylinder, the bridgepiece G, the diaphragm I, andthe adjustingscrew K, all substantially as specified.

4. The combination, with the vacuum-chamber of a vacuum-brake apparatus, of a locomotive-cylinder provided at each end with separate suction and discharge valves for air, whereby said cylinder is made to serve asan exhaustpump for exhausting air from said chamber, substantially as specified.

ROBT. HARDIE.

Witnesses FREDK. HAYNES, A. O. WEBB. 

